The present invention relates to electrical connections. More specifically, but not exclusively, the present invention relates to a semi-permanent connection between a bus bar and a connector contact. The present invention is also concerned with a connector contact and a connector for semi-permanent connection to a bus bar.
The use of bus bars to supply multiple loads from a single source of electric power is well known in the art and has found broad application in many power distribution settings. Examples of bus bars are found, amongst others, in automotive, industrial and residential installations.
Traditionally, soldered interconnections have been used in low voltage applications. However, with the increased modularization of components, solderless tab/socket combinations and associated cabling have been developed. Normally, the tab is inserted into the socket and selection of suitable shapes and materials is relied upon to insure that the contact pressure between the tab and the socket is sufficient to provide a good and durable electrical connection.
Alternatively, spring clips or leafs have been proposed to produce the necessary contact pressure. For example, U.S. Pat. No. 6,152,764 (Robinson et al.) issued on Nov. 28, 2000 discloses a watthour meter socket adapter which takes advantage of a spring clip to exert pressure on two contacting surfaces. Similarly, U.S. Pat. No. 6,178,106 B1 (Umemoto et al.) issued on Jan. 23, 2001 describes a power distribution centre including a spring clamp to urge a power terminal into contact with a bus bar.
In accordance with the present invention, there is provided a method of forming a semi-permanent connection between a substantially flat tab of a bus bar and a connector contact having first and second substantially flat, parallel and mutually facing contact tails, comprising inserting the flat bus bar tab between the first and second contact tails to form a sandwich structure, and spring clipping the sandwich structure whereby the flat bus bar tab is applied to both the first and second contact tails to thereby form the semi-permanent connection.
Preferably:
inserting the flat bus bar tab between the first and second contact tails comprises axially aligning the flat bus bar tab with the first and second contact tails;
covering the axially aligned bus bar tab and contact tails with an electrically insulating sleeve; and
the method further comprises at least partially covering the spring clipped sandwich structure with an electrically insulating housing.
The present invention further relates to a connector contact for semi-permanent connection to a generally flat tab of a bus bar, comprising:
at least one contact member for connection to an external electric conductor;
at least one generally flat contact tail electrically connected to the contact member and destined to overlap the bus bar tab; and
at least one U-shaped spring clip having a pair of claws defining a gripping region in which the bus bar tab and contact tail fit in overlapped position to form the semi-permanent connection between the bus bar tab and the contact tail.
According to preferred embodiments of the connector contact:
the generally flat contact tail is axial to the bus bar tab;
the generally flat contact tail is perpendicular to the bus bar tab;
the connector contact comprises first and second U-shaped spring clips for mounting on opposite sides of the overlapped busbar tab and contact tail;
the connector contact comprises first and second generally flat, parallel and mutually facing contact tails defining between them a spacing to fit the bus bar tab and thereby form with the bus bar tab a sandwich structure that fits in the gripping region defined between the pair of claws of the U-shaped spring clip;
the first contact tail comprises first and second opposite lateral edges, and first and second transversal slots opening in the first and second opposite lateral edges, respectively;
the second contact tail comprises third and fourth opposite lateral edges, and third and fourth transversal slots opening in the third and fourth opposite lateral edges, respectively;
the first U-shaped spring clip is mounted over the first and third lateral edges, and the second U-shaped spring clip is mounted over the second and fourth lateral edges;
the first U-shaped spring clip comprises a first transversal stabilising leaf for insertion in the first and third transversal slots in view of preventing axial movement of the first U-shaped spring clip on the first and second contact tails;
the second U-shaped spring clip comprises a second transversal stabilising leaf for insertion in the second and fourth transversal slots in view of preventing axial movement of the second U-shaped spring clip on the first and second contact tails; and
the connector contact comprises first and second generally flat, parallel and mutually facing contact members defining between them a spacing to fit the external electric conductor, the first contact member and the first contact tail are mechanically interconnected through a first bridge member, the second contact member and the second contact tail are mechanically and electrically interconnected through a second bridge member, and the first contact member and first contact tail are mechanically and electrically connected to the second contact member and second contact tail through a third bridge member.
Further in accordance with the present invention, there is provided a connector for semi-permanent connection to a generally flat tab of a bus bar, comprising at least one contact member for connection to an external electric conductor, at least one generally flat contact tail electrically connected to the contact member and destined to overlap the bus bar tab, at least one U-shaped spring clip having a pair of claws defining a gripping region in which the bus bar tab and contact tail fit in overlapped position to form the semi-permanent connection between the bus bar tab and the contact tail, and an electrically insulating housing for covering the contact tail and U-shaped spring clip.
According to a preferred embodiment of the connector:
the connector comprises two U-shaped spring clips for mounting on opposite sides of the overlapped busbar tab and contact tail;
the electrically insulating housing comprises an electrically insulating sleeve for covering the contact tail, the bus bar tab and the spring clips;
the bus bar is flat, and the sleeve comprises a proximal end with diametrically opposite slots for receiving the bus bar; and
the slots have respective closed ends, and the first and second spring clips comprise respective barbs for resting against the closed ends of the slots.
In accordance with another preferred embodiment of the connector:
the electrically insulating housing comprises an axial cavity in which said at least one contact member, said at least one contact tail, the bus bar tab and said at least one U-shaped spring clip are lying;
the cavity of the housing comprises a pair of opposite axial guiding ridges, said at least one U-shaped spring clip comprises two claws having respective slots, and the ridges are respectively lying in the slots of the claws; and
the bus bar tab extends in a direction perpendicular to the axial cavity of the electrically insulating housing.
The present invention is still further concerned with a connection assembly comprising a generally flat tab of a bus bar, a connector contact comprising at least one generally flat contact tail overlapping the bus bar tab, and at least one U-shaped spring clip having a pair of claws defining a gripping region in which the ovelapped bus bar tab and contact tail are fitted to form a semi-permanent connection between the bus bar tab and the contact tail.
Advantageously, the connection assembly further comprises an electrically insulating housing covering the contact tail and U-shaped spring clip.
The foregoing and other objects, advantages and features of the present invention will become more apparent upon reading of the following non restrictive description of preferred embodiments thereof, given for the purpose of illustration only with reference to the accompanying drawings.